Some offer 50% off, some are BOGO.
Example:
City of Chicago:
Get half off “adult” beverages every Thursday 4-8pm in August and September at participating Chicago locations. Visit your local Chipotle for the list of alcoholic drinks included in this promotion. Offer valid at participating Chicago Chipotle Mexican Grill locations each Thursday in August and September from 4-8 pm. May not be combined with other coupons, promotions, or special offers. Limited to one offer per person per day, subject to availability. 21+ with valid ID only. Void where prohibited; other restrictions may apply.